Final answer:
The sentence '¿De dónde eres usted?' is incorrect and should be replaced with '¿De dónde es usted?'.
Step-by-step explanation:
The sentence ¿De dónde eres usted? is incorrect. In Spanish, the formal way to ask someone where they are from is ¿De dónde es usted?. The verb 'eres' should be replaced with 'es' to agree with the formal pronoun 'usted'.
Learn more about Correcting a sentence in Spanish